Safety cutoff system for gas



April 29, 1952 ANsEN 2,594,430 GAS BURNERS RESPONSIVE TO AIR PRESSURE AND THERMOSTATIC CONTROL Filed Dec. 7, 194a G. V. H SAFETY CUTOFF SYSTEM FOR Y Z, y I

Attorney ven'ror:

Patented Apr. 29, 1952 OFFICE SAFETY CUTOFF SYSTEM FOR GAS BURNERS RESPONSIVE TO AIR jPRES- SURE AND THERMOSTATIC CONTROL Hans Gunner Viggo Hansen, Copenhagen.

Denmark Application December 7, 1946, Serial No.714,869 In Denmark June 15, 1946 1 Claim.

The present invention concerns a burner for a mixture of gas and compressed air by which the flow of the gas is automatically controlled by the flow or the air.

The drawing shows the parts in operating positions.

The compressed air for a gas burner G is supplied to a gas valve A which is closed by the pressure of the gas. A compressed air pipe C from a fan V to the gas burner G has a branch pipe S, with a bleed opening S, to the valve A which has a membrane A which is depressed by the air pressure so that the valve A is opened and the gas in a pipe line R1 can flow to burner G since the pressure of the air is made to exceed the pressure or the gas.

From this it will be seen that in case the compressed air iails no gas will be admitted to the burner G.

When compressed air and gas are admitted to the burner G the mixture should be ignited at once by the burning pilot flame D which is supplied with gas independent of the valve A through a pipe line R2.

To eiIect this result there is inserted in pipe S a valve 13 which, when its thermostatic element F is expanded by heat oi flame D, keeps the valve B open. When the element F contracts because the pilot flame D for some reason has been extinguished the valve B is closed by its spring B-l thus shutting oil the compressed air from the valve A.

In this way no gas will be admitted to the gas burner G if the pilot flame D is not burning.

Manually operated cut-off valves H1 and H2 are fitted to the pipe lines R1 and R2 to control operation.

I claim:

In a device for controlling the supply 01' combustible gas to a burner by thermostaticallycontrolled air pressure, the combination of a conduit adapted to lead to a burner for supplying gas under super-atmospheric pressure; a valve in said conduit; means including a flexible membrane subjected on one side to said gas pressure in said conduit and on which said valve is mounted; means forming a chamber sealed from said conduit by said membrane; a second conduit leading to said chamber; means for supplying air under pressure superior to said gas pressure to the burner foricombustion, means for diverting a portion of said air to said second conduit to flex said membrane to open said valve; a second valve in said second conduit biased to close said second conduit; means to supply a pilot flame for the burner; and a thermostatic element coacting with said second biased valve and disposed adjacent said flame-supplying means, expansible by heat from said flame to open said second biased valve.

HANS GUNNER VIGGO HANSEN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,856,408 Brear May 3, 1932 1,892,115 McKee Dec. 27, 1932 2,070,969 Carroll et a1. Feb. 16, 1937 2,147,568 Barber Feb. 14, 1939 2,263,896 Long Nov. 25, 1941 2,291,567 Wunsch et a1 July 28, 1942 2,335,471 Ashcraft Nov. 30, 1943 2,538,222 Wilson Jan. 16, 1951 FOREIGN PATENTS Number Country Date 463,150 Germany July 23, 1928 786,927 France June 24, 1935 628,621 Germany Apr. 8, 1938 448,534 Great Britain June 10, 1936 

